Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Effect of Aspect Ratio of Flat Tube on R410A Evaporation Heat Transfer and Pressure Drop

납작관의 종횡비가 R-410A 증발열전달 및 압력손실에 미치는 영향

  • Kim, Nae Hyun (Dept. of Mechanical System Engineering, Univ. of Incheon) ;
  • Lee, Eul Jong (Dept. of Mechanical System Engineering, Univ. of Incheon) ;
  • Byun, Ho Won (Dept. of Mechanical System Engineering, Univ. of Incheon)
  • 김내현 (인천대학교 기계시스템공학부) ;
  • 이을종 (인천대학교 기계시스템공학부) ;
  • 변호원 (인천대학교 기계시스템공학부)
  • Received : 2012.10.23
  • Accepted : 2012.12.03
  • Published : 2013.04.01
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Abstract

In this study, R-410A evaporation heat transfer tests were conducted in flattened tubes made from 5-mm round tubes. The test range covered a saturation temperature of $15^{\circ}C$, heat flux of $5{\sim}15kW/m^2K$, and mass flux of $200-400kg/m^2s$. The results showed that both the condensation heat transfer coefficient and the pressure drop increased as the aspect ratio increased, with a pronounced increase for an aspect ratio of 4. A comparison of the flattened tube data with existing correlations revealed that the heat transfer coefficients were reasonably predicted by the Shah correlation, and the pressure drops were reasonably predicted by the Jung and Radermacher correlation.

본 연구에서는 내경 5.0mm 원관을 납작하게 한 납작관에 대하여 R-410A를 사용하여 증발열전달 실험을 수행하였다. 실험은 포화온도를 $15^{\circ}C$로 고정한 상태에서 열유속을 $5{\sim}15kW/m^2$, 질량유속을 $200{\sim}400kg/m^2s$로 변화시키며 수행되었다. 실험결과 납작관의 종횡비가 증가할수록 열전달계수와 압력손실 모두 증가하였는데 특히 종횡비 4 인 경우 증가폭이 현저하였다. 납작관의 실험결과를 기존 상관식들과 비교한 결과 열전달계수는 Shah 상관식, 마찰계수는 Jung and Radermacher 상관식이 적절히 예측하였다.

Keywords

References

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